1. Field of the Invention
The present invention relates to a steering switch device attached to a steering wheel of an automobile, capable of enabling an operator to control a variety of electric devices.
2. Description of the Related Art
Conventionally, a steering switch device in which a plurality of operating knobs is arranged at arbitrary locations, for example, spoke portions for connecting an annular ring portion and a central pad portion, and in which a driver selectively operates the operating knobs with hands to activate a push button switch arranged in each of the operating knobs is known (for example, see Japanese Unexamined Patent Application Publication No. 2001-35312 (pages 4 to 6, FIGS. 2 to 6).
In such a steering switch device, each of the operating knobs is fixed on an upper surface of a case made of synthetic resin so as to be slidable and to be movable in the vertical direction, and the push button switch mounted on a circuit substrate is accommodated in the case. A lower portion of the case is opened, and the push button switch and the circuit substrate are inserted into the case from the lower opening end of the case. Further, the lower opening end of the case is covered with a cover, and the cover is bonded to the case to be integrated into one body using a plurality of screws. The case and cover constitute a switch housing, and the switch housing is fixed to a concave portion provided in the spoke portion.
However, in recent years, the types and the number of the operating knobs attached to the steering wheel have been increased along with diverse designs of steering wheels. Because of the trend, a steering wheel device in which the switch housing is fixed to a side portion of the pad portion and the operating knobs arranged on the upper surface of the switch housing are placed in a space surrounded by the ring portion and the pad portion has been required. According to the steering switch device, since the driver can easily operate the operating knobs without removing hands from the ring portion, it is possible to improve the operability of the operating knobs. However, a problem in external appearance is generated. Specifically, when the switch housing is fixed on the side surface of the pad portion, the surface appearance of the switch housing is gradually inclined toward the inner side so that the surface appears to form an inclined surface. Further, in the above-mentioned conventional steering switch device, the case and the cover constituting the switch housing is divided into two parts in the vertical direction, so that a dividing line (bonding line) between the case and the cover is really noticeable in the switch housing, which consequently deteriorates the appearance.